Post-mix beverages are generally supplied to the point of sale in concentrated form and are mixed in a container mounted on or connected to a dispenser. Alternatively they may be mixed immediately prior to being placed in a dispenser. Pre-mix beverages are simply poured into the container ready for dispensing. This is known as an open ended system. Any beverage which has a tendency to separate or stratify must be agitated prior to being dispensed. Conventionally open ended systems use, for example, an impeller, a paddle wheel or pump circulation to effect the agitation and prevent sedimentation. Such systems are described in U.S. Pat. Nos. 4,610,145, 3,664,643 and 4,008,832.
One serious problem with the aforementioned systems is that the beverages must be decanted into the mixing container in the dispenser. To ensure that bacteria and the like do not effect the quality of the beverage it is important that the container and agitating means, connecting pipe, pumps and other equipment are cleaned and sterilized regularly. In practice this is often not done and, particularly where a beverage remains in the mixing container for long periods, the quality of the beverage suffers. In fact, by simply decanting the beverage from the sealed and sterilized container in which it is supplied, the beverage comes into contact with the ambient atmosphere and hence any bacteria which might be present therein. To counter this problem, most beverage suppliers add preservatives to their beverages in order to improve the shelf life of the beverages or pasteurise the beverage before packaging. It is also becoming economically and technically viable to irradiate such commodities to preserve them against deterioration.
Many people object to the presence of preservatives in their beverages or object to taste and quality changes resulting from the treatments referred to.
It is accordingly an object of this invention to provide a fluid dispenser with which the aforementioned problems may be overcome or at least minimised.